1. Field of the Invention
This invention relates generally to generating and receiving modulated carrier waveforms, and more specifically, to optimizing the spectral occupancy of such modulated carrier waveforms.
2. Background Discussion
The demand for wireless data transmission far exceeds the available RF spectrum, especially since usable spectrum is a finite resource. In the United States, the Federal Communications Commission (FCC) has recently unlicensed some frequency bands that were historically reserved and licensed for television broadcast. Unused television channels are called “white space” spectrum. These white space frequencies are now open for unlicensed transmissions in locations where they do not interfere with either licensed television broadcasters or wireless microphones. Moreover, cellular service providers have paid billions of dollars to acquire licensed spectrum at auction. Such prices testify to the enormous value of spectrum and, in particular, the need for its efficient use.
Thus, embodiments of the present invention are, among other things, directed to transmitting high data rate signals that utilize narrow spectrum slices without interfering with other transmissions.